The central objective of the project is the production of a public use tape suitable for a study of aging among a random sample of 39,618 men mustered into the Union Army. The information in the tape will include socioeconomic characteristics of the households in which the recruits were raised; measures of the prevalence of specific diseases, of water supplies, and other public health conditions in the localities in which they lived during developmental ages; their combat and medical histories during the war; and their medical, occupational, income, residential, and demographic histories between 1965 and their deaths. Four projects will use the information in the tape to investigate such issues as: (1) The effect of nutritional status, socioeconomic factors, and exposure to diseases (including wartime stress) during developmental and middle ages on the morbidity and mortality rates of white males at middle and late ages. (2) The effect of host and environmental conditions on the probability that recruits would contract specific diseases during service and on the probability of dying from these diseases before being mustered out. (3) The effect of youthful exposure to virulent environments on the likelihood of developing specific chronic diseases and on the capacity to work at midadult and late ages, with controls for socioeconomic and other environmental conditions, age at exposure, and the duration of exposure. (4) The effect of specific chronic diseases on labor force participation and relative earnings at late ages during a period when the culture encouraged individuals late ages to be as self-supporting as possible. (5) The nature, cost, and effectiveness of arrangements for the care of the aged by the nature of their disabilities and by the occupations, family circumstances, and residence of those with whom they were lodged. (6) The contribution of economic, social, technological, political, and cultural factors to the sharp increase after 1890 in the income elasticity of the demand for leisure at older ages, and the explanation for the secular pattern of that increase. Other features of the project including the wide range of diseases to which the men in the sample were exposed, the capacity to follow highly mobile individuals over their life-cycles, the wide variations in the socioeconomic characteristics and environmental circumstances of the individuals, and the relatively low cost of the information per observation. Because of the nature of the 19th century diseases, the project also bears on the epidemiology of LDCS.